The number of described species on the planet is about 1.9 million, with ca. 17,000 new species described annually, mostly from the tropics. However, taxonomy is usually described as a science in crisis, lacking manpower and funding, a politically acknowledged problem known as the Taxonomic Impediment. Using data from the Fauna Europaea database and the Zoological Record, we show that contrary to general belief, developed and heavily-studied parts of the world are important reservoirs of unknown species. In Europe, new species of multicellular terrestrial and freshwater animals are being discovered and named at an unprecedented rate: since the 1950s, more than 770 new species are on average described each year from Europe, which add to the 125,000 terrestrial and freshwater multicellular species already known in this region. There is no sign of having reached a plateau that would allow for the assessment of the magnitude of European biodiversity. More remarkably, over 60% of these new species are described by non-professional taxonomists. Amateurs are recognized as an essential part of the workforce in ecology and astronomy, but the magnitude of non-professional taxonomist contributions to alpha-taxonomy has not been fully realized until now. Our results stress the importance of developing a system that better supports and guides this formidable workforce, as we seek to overcome the Taxonomic Impediment and speed up the process of describing the planetary biodiversity before it is too late.

The main objectives of this review are: 1) the compilation and updating of a reference database for Italian saproxylic beetles, useful to assess the trend of their populations and communities in the next decades; 2) the identification of the major threats involving the known Italian species of saproxylic beetles; 3) the evaluation of the extinction risk for all known Italian species of saproxylic beetles; 4) the or- ganization of an expert network for studying and continuous updating of all known species of saproxylic beetle species in Italy; 5) the creation of a baseline for future evaluations of the trends in biodiversity conservation in Italy; 6) the assignment of ecological categories to all the Italian saproxylic beetles, useful for the aims of future researches on their communities and on forest environments. The assess- ments of extinction risk are based on the IUCN Red List Categories and Criteria and the most updated guidelines. The assessments have been carried out by experts covering different regions of Italy, and have been evaluated according to the IUCN standards. All the beetles whose larval biology is sufficiently well known as to be considered saproxylic have been included in the Red List, either the autochtho- nous species (native or possibly native to Italy) or a few allochthonous species recently introduced or probably introduced to Italy in his- toric times. The entire national range of each saproxylic beetle species was evaluated, including large and small islands; for most species, the main parameters considered for evaluation were the extent of their geographical occurrence in Italy, and the number of known sites of presence. 2049 saproxylic beetle species (belonging to 66 families) have been listed, assigned to a trophic category (Table 3) and 97% of them have been assessed. On the whole, threatened species (VU + EN + CR) are 421 (Fig. 6), corresponding to 21 % of the 1988 as- sessed species; only two species are formally recognized to be probably Regionally Extinct in Italy in recent times. Little less than 65% of the Italian saproxylic beetles are not currently threatened with extinction, although their populations are probably declining. In forest environments, the main threats are habitat loss and fragmentation, pollution due to the use of pesticide against forest pests, and habitat simplification due to economic forest management. In coastal environments, the main threats are due to massive touristic exploitation such as the excess of urbanization and infrastructures along the seashore, and the complete removal of woody materials as tree trunks stranded on the beaches, because this kind of intervention is considered an aesthetic amelioration of seaside resorts. The number of spe- cies whose populations may become impoverished by direct harvest (only a few of large forest beetles frequently collected by insect traders) is very small and almost negligible. The Red List is a fundamental tool for the identification of conservation priorities, but it is not a list of priorities on its own. Other elements instrumental to priority setting include the cost of actions, the probability of success,and the proportion of the global population of each species living in Italy, which determines the national responsibility in the long-term conservation of that species. In this scenario, information on all species endemic to Italy, to Corso-Sardinia, to the Tuscan-Corsican ar- eas, and to the Siculo-Maltese insular system are given. A short analysis on relationships among beetle species traits, taxonomy, special- ist approaches, and IUCN Categories of Risk is also presented.

The most commonly used old‐growth forest indicators are structural attributes; nevertheless, they do not necessarily represent the biodiversity value of old‐growth forests. The aim of this study is to analyse the relationships between species richness data of different taxa and structural indicators of old‐growth and to identify taxonomic/functional groups, species and structural attributes that may be used as indicators of old‐growth. To achieve this goal we sampled forest structure, vascular plants, lichens, bryophytes, fungi, saproxylic beetles and birds in mature and old‐growth stands in southern Italy. We calculated Spearman’s correlation coefficients between species richness data and structural attributes. Analyses of indicator species, co‐occurrences and two‐way clusters were performed on the multi‐taxonomic list. The group of vascular plants most significantly correlated with other groups in terms of species richness; furthermore, it displays the highest proportion of between‐group co‐occurrences. The resulting multi‐taxonomic list of potential indicators may serve as an effective means of detecting and monitoring forest ecosystems; however, for this goal, structure‐based indicators, such as forest structural attributes and vascular plant species composition, are of primary importance.